The present invention comprises a new and distinct cultivar of grapevine botanically known as Vitis vinifera and hereinafter referred to as grapevine named ‘SV21-66-158’. As used herein, ‘grapevine’ refers to all plant parts including, vines, canes, tendrils, leaves, fruit and roots of ‘SV21-66-158’. Grapevine ‘SV21-66-158’ is the result of an effort to produce an early ripening, green, seedless table grape with fruit characteristics superior to currently available green grape cultivar ‘Thompson Seedless’ (unpatented). The new cultivar originated from a cross conducted in May 2000 near McFarland, Calif. between the female grapevine plant selection ‘13-2-138’ (unpatented) and the male grapevine plant ‘Princess’ (unpatented). Resultant ovules from the cross were harvested 42 days after pollination and cultured on ‘McCown's Woody Plant Medium’. Subsequently, the resultant embryonic plants were cultured in the same medium in the laboratory under twelve hours of light from standard fluorescent lamps at 29° C. The seedlings from this effort were transplanted to the greenhouse in November of 2001 and grown in the greenhouse at 29° C. with 12 hours illumination under high pressure sodium vapor lamps. The seedling population of 118 plants was planted in the field in the spring of 2001 near McFarland, Calif. The new grapevine was selected from this seedling population in July of 2003 and was then propagated by cuttings and grafted to ‘Freedom’ (unpatented) rootstock in 2004. The present invention has been found to retain its distinctive characteristics through successive asexual propagations.
‘SV21-66-158’ has not been sold or made publically available more than one year prior to the filing date of this application.